diff options
Diffstat (limited to 'source/blender/blenkernel/intern/gpencil_geom.cc')
| -rw-r--r-- | source/blender/blenkernel/intern/gpencil_geom.cc | 258 |
1 files changed, 220 insertions, 38 deletions
diff --git a/source/blender/blenkernel/intern/gpencil_geom.cc b/source/blender/blenkernel/intern/gpencil_geom.cc index 8ff026231f5..976b26a1f3a 100644 --- a/source/blender/blenkernel/intern/gpencil_geom.cc +++ b/source/blender/blenkernel/intern/gpencil_geom.cc @@ -541,64 +541,241 @@ bool BKE_gpencil_stroke_sample(bGPdata *gpd, bGPDstroke *gps, const float dist, } /** + * Give extra stroke points before and after the original tip points. + * \param gps: Target stroke + * \param count_before: how many extra points to be added before a stroke + * \param count_after: how many extra points to be added after a stroke + */ +static bool BKE_gpencil_stroke_extra_points(bGPDstroke *gps, + const int count_before, + const int count_after) +{ + bGPDspoint *pts = gps->points; + + BLI_assert(count_before >= 0); + BLI_assert(count_after >= 0); + if (!count_before && !count_after) { + return false; + } + + const int new_count = count_before + count_after + gps->totpoints; + + bGPDspoint *new_pts = (bGPDspoint *)MEM_mallocN(sizeof(bGPDspoint) * new_count, __func__); + + for (int i = 0; i < count_before; i++) { + memcpy(&new_pts[i], &pts[0], sizeof(bGPDspoint)); + } + memcpy(&new_pts[count_before], pts, sizeof(bGPDspoint) * gps->totpoints); + for (int i = new_count - count_after; i < new_count; i++) { + memcpy(&new_pts[i], &pts[gps->totpoints - 1], sizeof(bGPDspoint)); + } + + if (gps->dvert) { + MDeformVert *new_dv = (MDeformVert *)MEM_mallocN(sizeof(MDeformVert) * new_count, __func__); + + for (int i = 0; i < new_count; i++) { + MDeformVert *dv = &gps->dvert[CLAMPIS(i - count_before, 0, gps->totpoints - 1)]; + int inew = i; + new_dv[inew].flag = dv->flag; + new_dv[inew].totweight = dv->totweight; + new_dv[inew].dw = (MDeformWeight *)MEM_mallocN(sizeof(MDeformWeight) * dv->totweight, + __func__); + memcpy(new_dv[inew].dw, dv->dw, sizeof(MDeformWeight) * dv->totweight); + } + BKE_gpencil_free_stroke_weights(gps); + MEM_freeN(gps->dvert); + gps->dvert = new_dv; + } + + MEM_freeN(gps->points); + gps->points = new_pts; + gps->totpoints = new_count; + + return true; +} + +/** * Backbone stretch similar to Freestyle. * \param gps: Stroke to sample. - * \param dist: Distance of one segment. - * \param overshoot_fac: How exact is the follow curve algorithm. + * \param dist: Length of the added section. + * \param overshoot_fac: Relative length of the curve which is used to determine the extension. * \param mode: Affect to Start, End or Both extremes (0->Both, 1->Start, 2->End) + * \param follow_curvature: True for approximating curvature of given overshoot. + * \param extra_point_count: When follow_curvature is true, use this amount of extra points */ bool BKE_gpencil_stroke_stretch(bGPDstroke *gps, const float dist, const float overshoot_fac, - const short mode) + const short mode, + const bool follow_curvature, + const int extra_point_count, + const float segment_influence, + const float max_angle, + const bool invert_curvature) { #define BOTH 0 #define START 1 #define END 2 - bGPDspoint *pt = gps->points, *last_pt, *second_last, *next_pt; - int i; - float threshold = (overshoot_fac == 0 ? 0.001f : overshoot_fac); + const bool do_start = ELEM(mode, BOTH, START); + const bool do_end = ELEM(mode, BOTH, END); + float used_percent_length = overshoot_fac; + CLAMP(used_percent_length, 1e-4f, 1.0f); + if (!isfinite(used_percent_length)) { + /* #used_percent_length must always be finite, otherwise a segfault occurs. + * Since this function should never segfault, set #used_percent_length to a safe fallback. */ + /* NOTE: This fallback is used if gps->totpoints == 2, see MOD_gpencillength.c */ + used_percent_length = 0.1f; + } - if (gps->totpoints < 2 || dist < FLT_EPSILON) { + if (gps->totpoints <= 1 || dist < FLT_EPSILON || extra_point_count <= 0) { return false; } - last_pt = &pt[gps->totpoints - 1]; - second_last = &pt[gps->totpoints - 2]; - next_pt = &pt[1]; - - if (mode == BOTH || mode == START) { - float len1 = 0.0f; - i = 1; - while (len1 < threshold && gps->totpoints > i) { - next_pt = &pt[i]; - len1 = len_v3v3(&next_pt->x, &pt->x); - i++; + /* NOTE: When it's just a straight line, we don't need to do the curvature stuff. */ + if (!follow_curvature || gps->totpoints <= 2) { + /* Not following curvature, just straight line. */ + /* NOTE: #overshoot_point_param can not be zero. */ + float overshoot_point_param = used_percent_length * (gps->totpoints - 1); + float result[3]; + + if (do_start) { + int index1 = floor(overshoot_point_param); + int index2 = ceil(overshoot_point_param); + interp_v3_v3v3(result, + &gps->points[index1].x, + &gps->points[index2].x, + fmodf(overshoot_point_param, 1.0f)); + sub_v3_v3(result, &gps->points[0].x); + if (UNLIKELY(is_zero_v3(result))) { + sub_v3_v3v3(result, &gps->points[1].x, &gps->points[0].x); + } + madd_v3_v3fl(&gps->points[0].x, result, -dist / len_v3(result)); + } + + if (do_end) { + int index1 = gps->totpoints - 1 - floor(overshoot_point_param); + int index2 = gps->totpoints - 1 - ceil(overshoot_point_param); + interp_v3_v3v3(result, + &gps->points[index1].x, + &gps->points[index2].x, + fmodf(overshoot_point_param, 1.0f)); + sub_v3_v3(result, &gps->points[gps->totpoints - 1].x); + if (UNLIKELY(is_zero_v3(result))) { + sub_v3_v3v3( + result, &gps->points[gps->totpoints - 2].x, &gps->points[gps->totpoints - 1].x); + } + madd_v3_v3fl(&gps->points[gps->totpoints - 1].x, result, -dist / len_v3(result)); } - float extend1 = (len1 + dist) / len1; - float result1[3]; - - interp_v3_v3v3(result1, &next_pt->x, &pt->x, extend1); - copy_v3_v3(&pt->x, result1); + return true; } - if (mode == BOTH || mode == END) { - float len2 = 0.0f; - i = 2; - while (len2 < threshold && gps->totpoints >= i) { - second_last = &pt[gps->totpoints - i]; - len2 = len_v3v3(&last_pt->x, &second_last->x); - i++; + /* Curvature calculation. */ + + /* First allocate the new stroke size. */ + const int first_old_index = do_start ? extra_point_count : 0; + const int last_old_index = gps->totpoints - 1 + first_old_index; + const int orig_totpoints = gps->totpoints; + BKE_gpencil_stroke_extra_points(gps, first_old_index, do_end ? extra_point_count : 0); + + /* The fractional amount of points to query when calculating the average curvature of the + * strokes. */ + const float overshoot_parameter = used_percent_length * (orig_totpoints - 2); + int overshoot_pointcount = ceil(overshoot_parameter); + CLAMP(overshoot_pointcount, 1, orig_totpoints - 2); + + /* Do for both sides without code duplication. */ + float no[3], vec1[3], vec2[3], total_angle[3]; + for (int k = 0; k < 2; k++) { + if ((k == 0 && !do_start) || (k == 1 && !do_end)) { + continue; } - float extend2 = (len2 + dist) / len2; - float result2[3]; - interp_v3_v3v3(result2, &second_last->x, &last_pt->x, extend2); + const int start_i = k == 0 ? first_old_index : + last_old_index; // first_old_index, last_old_index + const int dir_i = 1 - k * 2; // 1, -1 - copy_v3_v3(&last_pt->x, result2); - } + sub_v3_v3v3(vec1, &gps->points[start_i + dir_i].x, &gps->points[start_i].x); + zero_v3(total_angle); + float segment_length = normalize_v3(vec1); + float overshoot_length = 0.0f; + + /* Accumulate rotation angle and length. */ + int j = 0; + for (int i = start_i; j < overshoot_pointcount; i += dir_i, j++) { + /* Don't fully add last segment to get continuity in overshoot_fac. */ + float fac = fmin(overshoot_parameter - j, 1.0f); + + /* Read segments. */ + copy_v3_v3(vec2, vec1); + sub_v3_v3v3(vec1, &gps->points[i + dir_i * 2].x, &gps->points[i + dir_i].x); + const float len = normalize_v3(vec1); + float angle = angle_normalized_v3v3(vec1, vec2) * fac; + + /* Add half of both adjacent legs of the current angle. */ + const float added_len = (segment_length + len) * 0.5f * fac; + overshoot_length += added_len; + segment_length = len; + + if (angle > max_angle) { + continue; + } + if (angle > M_PI * 0.995f) { + continue; + } + + angle *= powf(added_len, segment_influence); + + cross_v3_v3v3(no, vec1, vec2); + normalize_v3_length(no, angle); + add_v3_v3(total_angle, no); + } + if (UNLIKELY(overshoot_length == 0.0f)) { + /* Don't do a proper extension if the used points are all in the same position. */ + continue; + } + + sub_v3_v3v3(vec1, &gps->points[start_i].x, &gps->points[start_i + dir_i].x); + /* In general curvature = 1/radius. For the case without the + * weights introduced by #segment_influence, the calculation is + * curvature = delta angle/delta arclength = len_v3(total_angle) / overshoot_length */ + float curvature = normalize_v3(total_angle) / overshoot_length; + /* Compensate for the weights powf(added_len, segment_influence). */ + curvature /= powf(overshoot_length / fminf(overshoot_parameter, (float)j), segment_influence); + if (invert_curvature) { + curvature = -curvature; + } + const float angle_step = curvature * dist / extra_point_count; + float step_length = dist / extra_point_count; + if (fabsf(angle_step) > FLT_EPSILON) { + /* Make a direct step length from the assigned arc step length. */ + step_length *= sin(angle_step * 0.5f) / (angle_step * 0.5f); + } + else { + zero_v3(total_angle); + } + const float prev_length = normalize_v3_length(vec1, step_length); + + /* Build rotation matrix here to get best performance. */ + float rot[3][3]; + float q[4]; + axis_angle_to_quat(q, total_angle, angle_step); + quat_to_mat3(rot, q); + + /* Rotate the starting direction to account for change in edge lengths. */ + axis_angle_to_quat(q, + total_angle, + fmaxf(0.0f, 1.0f - fabs(segment_influence)) * + (curvature * prev_length - angle_step) / 2.0f); + mul_qt_v3(q, vec1); + + /* Now iteratively accumulate the segments with a rotating added direction. */ + for (int i = start_i - dir_i, j = 0; j < extra_point_count; i -= dir_i, j++) { + mul_v3_m3v3(vec1, rot, vec1); + add_v3_v3v3(&gps->points[i].x, vec1, &gps->points[i + dir_i].x); + } + } return true; } @@ -749,6 +926,7 @@ bool BKE_gpencil_stroke_shrink(bGPDstroke *gps, const float dist, const short mo second_last = &pt[gps->totpoints - 2]; + float len; float len1, cut_len1; float len2, cut_len2; len1 = len2 = cut_len1 = cut_len2 = 0.0f; @@ -759,11 +937,13 @@ bool BKE_gpencil_stroke_shrink(bGPDstroke *gps, const float dist, const short mo i = 0; index_end = gps->totpoints - 1; while (len1 < dist && gps->totpoints > i + 1) { - len1 += len_v3v3(&pt[i].x, &pt[i + 1].x); + len = len_v3v3(&pt[i].x, &pt[i + 1].x); + len1 += len; cut_len1 = len1 - dist; i++; } index_start = i - 1; + interp_v3_v3v3(&pt[index_start].x, &pt[index_start + 1].x, &pt[index_start].x, cut_len1 / len); } if (mode == END) { @@ -771,18 +951,20 @@ bool BKE_gpencil_stroke_shrink(bGPDstroke *gps, const float dist, const short mo i = 2; while (len2 < dist && gps->totpoints >= i) { second_last = &pt[gps->totpoints - i]; - len2 += len_v3v3(&second_last[1].x, &second_last->x); + len = len_v3v3(&second_last[1].x, &second_last->x); + len2 += len; cut_len2 = len2 - dist; i++; } index_end = gps->totpoints - i + 2; + interp_v3_v3v3(&pt[index_end].x, &pt[index_end - 1].x, &pt[index_end].x, cut_len2 / len); } if (index_end <= index_start) { index_start = index_end = 0; /* empty stroke */ } - if ((index_end == index_start + 1) && (cut_len1 + cut_len2 < dist)) { + if ((index_end == index_start + 1) && (cut_len1 + cut_len2 < 0)) { index_start = index_end = 0; /* no length left to cut */ } |